Valves and automatic control means therefor



July 11, 1961 D. E. GRISWOLD 2,991,796

VALVES ANO AUTOMATIC CONTROL MEANS THEREFOR 5 Sheets-Sheet 1 Filed Sept.30. 1954 ATTORNEYS A INVENTOR DAVID E. G-RlswoLD n uw l July 11, 1961 D,E. GRISWOLD 2,991,796

VALVES AND AUTOMATIC CONTROL MEANS THEREFOR 5 Sheets-Sheet 2 Filed Sept.50. 1954 ATTORNEYS July 11, 1961 D. E. GRlswoLD 2,991,795

VALVES AND AUTOMATIC CONTROL MEANS THEREFOR Filed Sept. 30, 1954 5Sheets-Sheet 3 INVENTOR. DAVID E. GmswoLn K7/jm SLM ATTORNEYS July 1l,1961 Filed Sept. 30. 1954 D. E. GRlswoLD 2,991,796

VALVES ANO AUTOMATIC CONTROL MEANS THERETOR 5 Sheets-Sheet 4 INVENTOR.DAVID E. G-mswoLD BYKWU y@ ATTO RN EVS uly 11, 1961 D. GRlswoLD v2,991,796

VALVES AND AUTOMATIC CONTROL MEANS THEREFOR Filed Sept. 30, 1954 5Sheets-Sheet 5 7f3 a INVENTOR I 7 zLJ BY DAVID RswD I ORNEYS UnitedStates Patent flice Patented `l'uly 11, 1961 2 991,796 VALVES ANDAUTMATIC lCONTROL MEANS THEREFOR David E. Griswold, San Marino, Calif.,assignor to Donald G. Griswold, Alhambra, Calif. Filed Sept. 30, 1954,Ser. No. 459,496 16 Claims. (Cl. 137-489) This invention relates tovalves and, more particularly, to main valves having variouscombinations of automatically operable control elements associatedtherewith to eiect pressure regulation, pressure relief, etc. while atthe same time controlling theopening and/or closing speed of said mainvalves.

The invention broadly contemplates automatic valves with which means areincluded for controlling the speed of the valve opening and closingoperations, whereby these operations may be performed at the same or atdifferent selected speeds. On one embodiment thereof, the invention isespecially advantageous in ,providing automatic valves for installationsin which it is desirable to quickly accomplish one valve operation andto more slowly accomplish the reverse operation. For example, in somevalve installations it is necessary to provide a valve that has a fastclosing action and a slow opening action. Prior to the presentinvention, valves constructed for fast closing usually also provided`for fast opening. However, where the system does not require fastopening it is more desirable that the valve open at a slower rate toavoid pulsations of delivery pressure. In systems requiring maintenanceof a critical pressure condition on the outlet or downstream side of thevalve, a fast opening valve presents a major problem due to thepulsation or cycling of the valve and consequent uttering or pulsationof the delivery pressure.

It is desirable in some systems to provide a valve that has a fastclosing rate and a relatively restricted opening rate. For example, in asystem employing an automatic pressure reducing valve, the valve shouldpreferably close rapidly to correct any excess pressure condition on itsdownstream side and reopen slowly at a controlled rate to avoid creatingsuch condition.

It is desirable in other systems to provide a valve that has a fastopening operation and a relatively restricted closing rate. This istrue, for example, of systems employing automatic pressure relief valveswherein it is desirable to provide a valve which will open quickly totake care of excessive pressure, or sudden surges in the pipe line, andwhich will close at a relatively slower, controlled rate to prevent lineshock, chatter, and slamming of the valve disk against the seat.

Another example, in which a fast opening and slow closing valveoperation is advantageous, is in systems employing float-controlledValves in a supply line to maintain a constant liquid level in areservoir served by such line. In order to keep up with changes inreservoir level and maintain a substantially constant head of liquid, itis necessary that the valve in the supply line be quick opening.However, it is usually desirable to restrict the closing speed so thatin the event that there is a sudden decrease in demand on the reservoir,the valve will not be allowed to close at a rate more rapid than can betolerated in order to avoid water hammer or line shock that wouldotherwise result from stopping the liquid flow,

Another application of the invention resides in the provision of acontrol valve 4wherein both opening and closing operations areaccomplished at a relatively slow adjustable rate. Such a valve isparticularly advantageous for use with centrifugal pumps wherein it isdesirable Vto start the pump against a closed valve, and to then slowlyopen such valve, and to slowly reduce y2 the velocity in the dischargeline by gradually closing the valve before thepump is stopped. l

The present valves and control combinations provid relatively simpleapparaus for accomplishing thetypes of control referred to above. Inaddition, the control elements provide for great sensitivity ofoperation of 'the main valves associated therewith and are readilyadaptable for accomplishing a wide variety of valve control operations.

Accordingly, the principal object of this invention lis to provideautomatic valves having means connected therewith to selectively controlthe rate of opening and of closing, whereby the opening and closingoperations may be accomplished 'atthe same or at diierent selectedspeeds.

Another object is to provide automatic lmain valve and controlcombinations in whichthe control elements thereof may be readilyarranged to provide `different modes of operation of the main valve andalso provide great flexibility in the control of the valve opening andclosing rates.

Another object is to provide automatic valves of the type describedwherein the function of controlling the opening and closing rates isaccomplished by the provision of means of more simple construction andim'- proved sensitivity than previously obtainable.

Another object is to provide an automatic valve having means providing afast closing speed and a relatively restricted opening speed, therebysubstantialy dampening out any tendency of the valve to pulsate duringor after opening.

Another object is to provide an automatic valve having means providing afast opening action and a more slowly operating closing action.

Another object is to provide automatic valves having means to provideindependently adjustable opening and closing rates.

These and other objects and advantages hereinafter apparent from theensuing description are accomplished in accordance with the presentinvention by the utilization of novel combinations of a lluid pressureoperable main valve, an associated pilot valve or other controlapparatus for controlling the supply of operating uid to and the exhaustof operating uid Vfrom the pressure chamber of the main valve, and oneor more adjustable, combined needle and check valves for regulating therate of flow of said operating duid to and from said chamber.

The arrangement of the combined needle and check valve in thecombination determines whether the main valve is fast opening and slowclosing in response -to the associated pilot valve, or other controlmember, or whether the reverse mode of operation takes place. `Incertain embodiments of the invention more than one combined needle andcheck valve may be employed lin the assembly in order to selectively andadjustably control both opening and closing operations of the mainvalve.

The invention will be more fully understood by reference totheaccompanying drawings in which:

FIG. l diagrammatically illustrates a pressure-reducing valvecombination including a main valve, a pilot valve, and a combined needleand check valve, the main valve being in open position and the parts ofthe combination being arranged to provide quick closing of the mainvalve in response tothe pilot valve upon development-df excessivedownstream pressure and a more restricted opening rate as determined bythe combined needle 'and check valve upon return ofnormal pressure;

FIG. 2 is a diagrammatic illustration similar'to FIG. fl but in whichthe main valve and pilot valve are showh in the closed 'position theyassume upon excessive downstream pressure and in which the needle and'check valve 3 is shown in an adjusted position different from that fFIG. 1;

FIG. 3 diagrammatically illustrates a pressure relief valve combinationincluding a main valve, a pilot valve, and a combined needle and checkvalve, in which the needle and check valve is arranged in thecombination in such a manner that the main valve is fast opening but isslow closing to prevent back surges, the parts of the apparatus beingshown in the position they assume when the main valve and pilot valveare open;

FIG. 4 is a diagrammatic illustration similar to FIG. 3, but in whichthe main valve and pilot valve are shown in closed position;

FIG. 5 diagrammatically illustrates the arrangement of a power-operatedmain valve, having pressure chambers on each side of a diaphragm, with apilot valve, and a pair of combined needle and check valves, whereby themain valve has a fast closing action and a relatively restricted openingaction;

FIG. 6 diagrammatically illustrates the arrangement of a power-operatedmain valve and pilot valve with a pair of combined needle and checkvalves, whereby the main valve has a fast opening action and arelatively restricted closing action;

FIG. 7 is a vertical sectional view through a combined needle and checkvalve employed in the apparatus of FIGS. l through 6 showing the needlevalve in a position of maximum restriction;

FIG. 8 is a View similar to FIG. 7 showing the needle valve in itsposition of minimum restriction;

FIG. 9 is an enlarged sectional view showing the construction of thedisk which serves as a check valve in the combined needle and checkvalve shown in FIGS. 7 and 8; and

FIG. 10 is a similar view showing a modified form of check valve disk.

Referring now to the drawings in detail ,and in particular to FIGS. land 2, thereof, which illustrate a quick-closing slow-opening valvecombination especially adapted for pressure regulation on the deliveryside, there is shown a main valve M, a pilot valve P, and a combinedneedle and check valve N. The main valve M comprises a body 16, a covermember 17 and a flexible diaphragm 18 disposed intermediate said bodyand cover. The body 16 is provided with an inlet chamber 19 and anoutlet chamber 20 separated by a partition including an upright wall 21and a downwardly extending wall 22, which provide an opening to receivea valve seat 23. Seat 23 is provided with a plurality of radial arms23a, which merge centrally and provide a guide 24 for the lower end of avalve stem 25. The upper end of the valve stem 25 is guided in a bushing26 mounted in the cover 17. Valve stem 25 extends through a centralopening in the diaphragm 18 and carries a disk-like diaphragm supportingplate 27, which engages a portion of the upper surface of the diaphragm18 and also carries a lower diaphragm supporting member 28 which engagesa portion of the lower side of said diaphragm. The member 28 has aninwardly projecting ange 29 at its lower side provided with an annularrecess 30 in which an annular sealing ring 31 is seated. The sealingring 31 is adapted to engage the upper surface of the seat 23 when thevalve is closed to prevent all flow between the inlet chamber 19 and theoutlet chamber 20. A supporting disk 28a holds the sealing ring 31 inposition and also supports the lower diaphragm supporting member 28. Alock nut 32 in cooperation with an enlarged portion 33 on the valve stem25 secures the upper plate 27, diaphragm 18, lower diaphragm supportingmember 28, and supporting disk 28a in assembled relation. The covermember 17 is constructed to provide a chamber 34 above the diaphragm 18to receive fluid under pressure for effecting downward flexing of thediaphragm to cause the sealing ring 31 to engage with the seat 23 andthus close the valve M. The

valve stem 25 is spring-loaded in a conventional manner by a spring (notshown) contained in pipe nipple 25a.

The inlet chamber 19 of the valve M is connected by a conduit 35 to anejector-strainer generally designated at 36, which is in turn connectedthrough the needle and check valve N, and a conduit 37 to the pressurechamber 34 of the main valve, and through conduit 38 to the inlet ofpilot valve P. The outlet of pilot valve P is connected to the outletchamber 20 of the main valve M by a conduit 39.

The ejector-strainer 36 may be of any conventional type and is shown ascomprising a housing 40 accommodating a strainer assembly 41, whichthreadedly engages said housing at one end thereof and may be readilyremoved for cleaning or replacement. The strainer member 41 has aninternal passage 42 provided at one end with a series of holes 43 forthe passage of liquid. A cylindrical screen 44 covers the end of thestrainer in the area of the holes 43. The internal end of the assembly41 is provided with a nozzle 45 for forming a primary jet adapted tocooperate with a nozzle 46 in the other end of the body member 40 forforming a secondary jet. The end of the strainer assembly 41 oppositethe nozzle 45 is provided with a plug 47, which may be removed forcleaning puiposes. The body member 40 is further provided with a pair oflateral bosses 48 and 49 in which openings are provided for receivingone end of the conduit 35 and fitting 50 of the needle valve N,respectively. The nozzle 46 is disposed in a member 51, which threadedlyengages member 40 and is provided with a central opening for receivingone end of the conduit 38. The ejector-strainer 36 thus prevents theentrance of foreign matter from the main line into the control elementsthereby ensuring trouble-free operation, and also provides an ejectoraction for facilitating removal of fluid from the operating chamber 34of the main valve M and reducing the pressure therein.

The combined needle and check valve N, shown in greater detail in FIGS.1S and 16, comprises a housing 60 provided with aligned bores 61 and 62in the ends thereof and with another bore 63 in its intermediate portionextending normally to the aligned bores 61 and 62. Bores 61, 62 and 63all communicate with a chamber 64 within the housing 60.

In the manner in which the valve N is installed in the system of FIG. 1,bore 61 serves as an inlet for the flow of fluid through the housing 60and is internally threaded as at 65 for the reception of the tting 50which in this embodiment of the invention connects the needle valve N tothe ejector-strainer 36. Bore 63 serves as an outlet and is internallythreaded as at 66 to receive a fitting 68a which connects said bore withone end of the conduit 37, which is connected to the iluid pressurechamber 34 of the main valve M.

The bore 62 includes axially spaced enlarged portions 67 and 68 (FIG. 7)and a relatively restricted intermediate portion 69 which providesshoulders 70 and 71 adapted to limit adjusting movement of a valve stem72, as hereinafter described. The enlarged portion 67 is threaded forthe reception of a correspondingly threaded portion 73 of the valve stem72. An annular groove 74 in the restricted portion 69 of the bore 62 isprovided with a conventional O-ring 75 to form a liquid-tight sealbetween the chamber 64 and the enlarged portion 67 of the bore 62. Thetting 50 is provided with a central passage or bore 76 which constitutesa port for the flow of liquid in either direction, and is furtherprovided at its upper or inner end with a valve seat 77 adapted tocontact a closure member or check valve disk 78. A gasket 79 preventsleakage between the fitting 50 and the housing 60.

The valve stem 72 has a reduced portion 80 at its lower end of a smoothcylindrical construction, which adjoins a tapered or conically shapedtip 81. The check valve disk 78 has a central bore 82 which surrounds'the reduced cylindrical endl-'portion 80, or the tapered end portion81, of the valve stem, as shown in lFIGS. 7 and 8, respectively,depending upon the degree of adjustment of the needle valve. Theenlarged portion 73 of the valve stem 72 terminates in an abutment 67aadapted to engage the shoulder '70 to limitthe movement of said valvestem to its position of minimum opening relative to the disk 78, asshown in FIG. 7. A lockwasher 83 in a groove provided in the lowe'rportion "of fthe mid-section of the valve stem 72 is adapted 'to contactshoulder 71 at the point of maximum opening adjustment of said valvestem (FIG. 8) and provides a stop therefor.

The check valve disk 78 is normally urged by a compression spring 84into engagement with the valve seat 77 on the fitting 50. As is bestshown in FIGS. 9 and l the inner wall defining the bore 82 of the disk78 is provided with an interrupted or serrated surface similar to thatof a fluid pack. To accomplish this end, the bore 82 may be tapped witha conventional thread tap to provide a shallow helical groove 86, asshown in FIG. 9 which extends substantially the length of the bore butterminates short of the upper end thereof. The cylindrical stem portion80 may have a clearance of about one thousandth (0.001) to twothousandths (0.002) of an inch with respect to the cylindrical surfaceof the bore 82. With this construction, a turbulent low is imparted tothe liquid llowing from bore 63 into passage 76, through the slightclearance space between the wall of the bore 82 and the needle valvestem 80. This materially reduces the llow rate permitting a very lineadjustment, particularly when the stem portion 80 is adjusted so that itoccupies the full length of the bore 82 to provide maximum restrictionin the manner illustrated in FIG. 7.

In the modification shown in FIG. l0, the lluid .pack is obtained in thebore 82:1 of the disk 78a by providing therein a series of spacedshallow annular grooves 87.

In order to obtain the desired adjustment of the valve stem portion 80by advancing it in or out of the bore 82, the upper end of the valvestem 72 is provided with a kerf 88 for the reception of a screw driver.A lock nut 89 is provided to maintain the needle Valve stem 72 in aselected adjusted position, and a cap 90 is mounted on a threadedextension 91 at one end of the housing 60 to enclose and thus protectthe adjusting mechanism against damage or unauthorized tampering.

The adjustable mounting of the needle valve stern 72 is such that whenit is screwed outwardly the tapered end 81 of the stem increases theclearance between the stem and the bore 82 of the disk 78, andcorrespondingly increases the flow volume through this Vmemberfrom bore63 to passage 76, so that any desired rate of iiow within the capacityof the needle valve device N canbe ellected through adjustment of saidValve stem. It will be understood that the described constructionprovides for an extremely sensitive adjustment of the ilow of fluidthrough the valve.

The operation of the combined needle and check valve N will be readilyapparent. Thus, when a suiicient pressure dillerential exists frompassages 76 to bore 63 to overcome the force of the spring 84, thedisk78 will be lifted upwardly from its seat 77 and will slide along thevalve stem portion 80 so that substantially unrestricted flow of fluidwill be permitted from passage 76 to bore 63. On the other hand, if thedirection of 'greater pressure is reversed, the disk 78 will move toclosed position very rapidly under the combined action of the fluidpressure and spring pressure, and the disk 78 will quickly positionitself on the seat 77. Flow in this direction'is therefore restrictedvin accordance with a desired preadjusted position of the valve stemportion 80 relative yto the bore or orifice 82 in the disk V78. It willtherefore befseen that the combined needle land check valve employedherein Will `permit substantially unrestricted flow in one direction andan extremely nely adjustable restricted flow in -the op- -positedirection. 'The construction of this combined needle Aopening 102connected to one end of conduit 69. A partition 103 extending inwardlyinto the valve body 100 is Yprovided with a channel 104, whichcommunicates with the opening 101. The partition 103 is provided 'with avalve seat 105, which in cooperation with a valve disk 106 is adapted tocontrol the flow of operating lluid through the pilot valve P andthereby control the operation of the main valve M. Valve disk 106 isheld by a disk retainer 106:1 which threadedly engages a yoke-like valvestem 107. The stem 107 is adapted to be reciprocably operable inresponseto the action of a diaphragm 108 to urge disk 106 toward or awayfrom its seat 105. The diaphragm 108 is secured to the valve stem 107between an enlarged top portion 109 and a top plate 110 by means of anut 111. The marginal edge of the diaphragm 108 is positioned betweenthe body member 100 and a cover 112, which are held in assembledrelation by screws 113. The cover 112 contains a compression spring 114,one end of which bears on the nut 111 above the diaphragm and the otherend of which bears against an adjustable spring guide 115. The spring114 tends to move the disk 106 away from the seat 105 to by-passoperating fluid around the chamber 34. An adjusting screw 116 threadedlyengaging a bore 117 in the cover 112 provides for adjustability of thespring guide 115, whereby the pilot valve spring pressure may beadjusted to a predetermined set value. Lock nut 118 enables theadjusting screw 11 to be retained in any desired position.

The assembly shown in FIGS. 1 and 2 is especially useful as a pressurereducing device, wherein the main valve M functions primarily to limitthe downstream pressure so as not to exceed a given pressure, asdetermined by the setting of the pilot valve P, and wherein it isnecessary that the main valve have a fast closing operation. In theVarrangement shown, the valve M will provide the desi-red fast closingoperation, but will open more slowly and therefore eliminate thediliiculties heretofore caused by fluttering or pulsation of deliverypressure. Accordingly, in operation, should the pressure in thedownstream chamber 20 of the main valve M become excessive or greaterthan the set pressure of spring 114 of the pilot valve P, diaphragm 108of the pilot valve will be exed so as to partially or completely closethis valve (as i'n FIG. 2) by urging the valve closure disk 106 againstthe valve seat 105, thereby preventing by-passing of operating fluidfrom the inlet 19 of main valve M through conduit 35, ejector-strainer36, and pilot valve P to the downstream chamber 20. Suliicient fluidpressure will then immediately build up in the passage 76 to urge checkvalve disk 78, of the combined needle and check valve N, from its seat77, thereby admitting operating iluid at full line pressure into thechamber 34 of the main Valve M through the conduit 37. This in turn willcause the diaphragm 18 of the main Valve M to be yflexed downwardlytoquickly close this Valve.

When the downstream pressure has been reduced suficiently to cause thepilot Valve P to again open, as shown in FIG. 1, iluid will llow throughconduit 35, nozzles 45 and 46, conduit 38, and through the pilot valve Pand conduit 39 to the downstream chamber 20l of the main Valve.Thus',the by-passing of operating fluid will be resumed to permit themain valve M to remain open. The action of the jets produced by thenozzles '45- and 46 will cause lluidto be Withdrawn from the chamber 34of the main valve M at a`rate controlled by the adjustment of the needlevalve stem port-ion of the valve N. Thus,

Awithin the capacityofthe setting .of theneedle'valvefN,

the rate of opening of the main valve M can be closely controlled. Bypositioning the needle valve stem portion 80 as shown in FIG. 1, therate of opening of the main valve M is adjusted to its maximum speed,Whereas by positioning the needle valve stem as shown in FIG. 2, therate of opening of the main valve is adjusted to the minimum. Anyadjustment between the limits shown may be quickly made by turning theneedle valve stem 72 as desired.

It will be understood that the pilot valve P will automatically openmore or less, or close, in accordance with the variations in pressure onthe downstream side of the main valve M, and that said main valve willcorrespondingly modulate in its operation, as required, to maintain asubstantially constant pressure on its downstream side.

FIGS. 3 and 4 illustrate another embodiment of the invention wherein themain valve and control means is adapted to automatically maintainconstant line pressure by by-passing or relieving excess pressure from amain line. In this embodiment, the main valve M may be placed in aby-pass line or pressure relief line designated 120. Since a reliefvalve is intended primarily to open to dissipate any normally excessivepressure at the inlet side of the valve, it is desirable that this typeof valve be fast opening. It is permissible, however, in such usage tohave a valve with ra slow closing arrangement. The combination shown inFIG. 3 provides a fast opening main valve M which is adapted to closemore slowly at an adjustable rate, whereby undesirable pulsations orwater hammer are avoided.

The main valve M, as shown in FIG. 3, is similar to that previouslydescribed with respect to FIGS. l and 2, the difference in operation ofthe valve being the result of `a different combination of controlelements. Thus, the conduit 35 from the inlet side of the main valve Mis connected to a T 121, which connects this conduit through a line 122of reduced size to the operating chamber 122:1 of a power-operated pilotvalve generally designated as P-l. T 121 Ialso connects conduit 35, bymeans of a conduit 123, through a conventional strainer and needle valvegenerally designated at 124, and through a T 125, and conduit 123:1, tothe inlet chamber of the pilot valve P-1. A conduit 126 further connectsT 125 to the outlet opening of a combined needle and check valve N,similar in construction to that shown in FIG. l and `described above.The combined needle and check valve N is connected by the tting 50 tothe pressure chamber 34 of the main valve M. It will be noted that thecombined needle and check valve N is shown installed in a reverse mannerwith respect to the main valve chamber 34 from that shown in FIG. l.Accordingly, the valve M instead of being fast closing and slow opening,as in FIG. l, is now arranged for fast opening and slow closing.

The pilot valve P-1 shown in FIG. 3 differs in structure from the pilotvalve P shown in FIG. 1, in that it is power or pressure `fluid operatedin response to pressure from the inlet side of the main valve to controlthe flow of operating fluid to and from the chamber 34 of the main valveM. Pilot valve P-l comprises a valve body 127 having an inlet opening128 to which the conduit 123:1 is connected, and an outlet opening 129to which one end -of the conduit 39 extending from the downstreamchamber 20 of the main valve is connected. A partition 130 in the valvebody 127 separates the inlet and outlet openings 128, 129, respectively,and serves as a support for an annular valve seat 131. The body 127 hasa central opening 132 axially aligned with the seat 131. A generallyspool shaped intermediate valve section 133 is disposed above the valvebody 127 and an annular gasket 134 is disposed between said intermediatesection and said valve body. A plurality of studs 135 is mounted in thebody 127 and extends through suitable openings in the gasket 134 andthrough a ange at the lower end of the intermediate section 133. Nuts136 mounted on the studs secure the valve section 133, gasket 134 andvalve body 127 together in leak proof relation. The intermediate section133 has a transverse wall 137 provided with a central opening in which avalve stem 138 is slidably mounted. The valve stem 138 has a recessedenlargement at its lower end and carries a valve disk 139 adapted toengage the valve seat 131 and shut oi the ow of uid through valve P-1.

The intermediate section 133 also has a Aflange 140 at its lower end. Ailexible diaphragm 141 overlies the ange and a cover 142 has a ilange143 engaged with the upper side of said diaphragm. A plurality of screws144 secure the cover 142 and the diaphragm 141 to the flange 140. Thevalve stem 138 has a shoulder 145 disposed above the transverse wall 137which forms an abutment for a diaphragm supporting washer 146 at thelower side of the diaphragm 141. A similar Washer 147 is mounted uponthe stem above the diaphragm 141 and is internally threaded so that italso serves as a clamping nut for securing the diaphragm 141 to thevalve stem 138.

The cover 142 has a threaded boss 149 in which an adjusting screw 150 ismounted. A compression spring 151 is disposed within the cover 142 andits lower end is engaged with the Washer 147 and its upper end isengaged with a spring guide 152 that bears against the inner end of theadjusting screw 150. A jam nut 153 locks the screw 150 in position. Theintermediate section of the valve 133 provides a pressure chamber belowthe diaphragm 141 and an opening 154 in the cylindrical wall of thissection accommodates the conduit 122 as previously described. An O-ringpacking member 15S is mounted in the transverse wall 137 and forms aseal around the valve stem 138 between the outlet chamber 132 of thevalve body 127 and the valve operating pressure chamber. The valve cover142 has a vent opening 156 which connects the upper side of thediaphragm 141 to the atmosphere.

The strainer and needle valve 124 comprises a housing 160 having inletand outlet ports 161 and 162, respectively. The housing contains aconventional strainer 163 and is provided with plugs 164 and 165 forcleaning purposes. A partition 166 separates the inlet and outlet ports161 and 162 and is provided with a restricted orice 167, the openingarea of which may be controlled by an adjustable needle valve 168.

In the operation of the combination of FIGS. 3 and 4 for automaticpressure relief in the line 120 the main valve M and the pilot valve P-1would normally be in closed position, as shown in FIG. 4, assumingnormal pressure to be below the set operating pressure of the pilotvalve P-l.

The main valve M would then be maintained in closed position by thepressure of the liquid in the chamber 34, in combination with thepressure of the spring (not shown) acting on the valve stem 25, whichnormally urge the valve stem and diaphragm 18 downwardly and the valvedisk 31 towards its seat 23. Upon a pressure surge at the inlet side 19of the main valve M, the pressure would be quickly transmitted to thechamber 122a of the pilot valve P-1 through the conduit 35 and line 122.The diaphragm 141 of the pilot valve P-1 would, therefore, be exedupwardly against the pressure of spring 151 urging the valve disk 139from its seat 131, as shown in FIG. 3, and thereby opening the valve P-lpermitting operating uid to drain from pressure chamber 34 of the mainvalve M through conduit 126 and conduit 39 to the outlet chamber 20 ofthe main valve, at a rate faster than liquid can be supplied from theinlet chamber 19 of said main valve through the restricted opening 167of the needle valve 124. During this operation, the check valve member78 (FIG. 3) of the combined needle and check valve N will be raised fromits seat permitting unrestricted iiow of operating uid from the valvechamber 34. 'The pressure in the inlet .chamber 19 will cause the mainvalve disk 31 .to be raised from its seat 23 and the main valve willquickly lopen, as shown in FIG. 3, permitting full -flow of liquid fromchamber 19 thus providing rapid pressure release.

The operation just described provides substantially instantaneousopening of the main valve M in response to pressure in the chamber 19above the predetermined set value of the pilot valve P-1. After thepressure in chamber 19 has been reduced below the normal operatingpressure of valve P-1, the spring 151 will cause this valve to close, asshown in FIG. 4, thereby preventing the flow of fluid from diaphragmchamber 34 of the main valve M to the outlet chamber 20 of this valve.Accordingly, fluid flowing through the needle valve 124 and through thecombined needle and check valve N will enter operating chamber 34 andwill act in cooperation with the spring loading of valve M to slowlyclose the Valve M at a rate dependent upon the setting of the lneedlevalve stem portion 80 in the combined needle and check valve N. It willbe understood that the area of the opening between the needle valveportion 80 of the valve N and the bore 82 of the check valve disk 78will be less than the area of the orifice 167 of the needle valve 124,and that the valve N will provide a much more sensitive adjustment ofthe rate at which the valve M closes than will said valve 124.

FIG. illustrates another embodiment of the invention wherein the valve Min the system shown in FIGS. l and 2 is replaced by a power operatedvalve M-1 comprising a body 200, an intermediate spool-shaped section201 and a cover member 202. A diaphragm 203 is interposed between theintermediate section and cover member. The body 200 is provided with aninlet charnber 204 and an outlet chamber 205 separated by a partition206, which provides an opening to receive a valve seat 207. The body 200has a central opening 208 axially aligned with the seat 207. Thespool-shaped interu mediate section 201 is disposed above the valve body200 and an annular gasket 209 is provided between the intermediatesection and the valve body. Studs 210 provided with nuts 211 hold theseparts in assembled relation. The intermediate section 201 has atransverse wall 212 provided with a central opening containing a bushing213 in which a valve stem 214 is slidably mounted. A plate 215, held tothe wall 212 by screws 216 and having a central opening to accommodatethe valve stem 214, retains the bushing 213 in proper position. AnO-ring 217 is provided in a groove in bushing 213 to prevent leakage offluid along the valve stem 214. The lower portion of the valve stem 214has a bore 218 which slidably receives a member 219 attached to a plate220 carrying a sealing ring 221. The plate 220 bears against a flange222 on the member 219 and is held thereagainst by a llock nut 223, whichthreadedly engages the lower end of member 219. A retainer ring 224holds the ring 221 in position on the plate 220. A spring 225 isprovided between the top of plate 220 and the bottom of intermediatesection 201 to urge the valve closure assembly downwardly toward itsclosed position in the event of pressure failure, irrespective of theposition of valve stem 214.

The cover member 2012 and diaphragm 203 are held in assembled relationwith the intermediate section 2011 by studs 226 and nuts 227. The valvestem 214 has a shoulder 228, which forms an abutment for a diaphragmsupporting washer 229 at the lower side of the diaphragm 203. A similarwasher 230 is mounted upon the stem above the diaphragm 203 and is heldin place by a lock nut 231. A bushing 232 is provided in the covermember for maintaining the valve stem 2114 in axial alignment. A plug233 seals the pressure chamber 234 above the diaphragm 203. The valveM-l is operated by the pressure differential in the fluid pressurechamber 234, above the diaphragm 203 and in the fluid pressure chamber235 below said diaphragm. These operating cham- .bers are connected byconduits37 and 250, "respectively,- to the inlet sides of combinedneedle and check valves N-1 and N-2, respectively. The combined needleand check valves N-1 and N-2 are of the same structure as the valve Ndescribed in Vconnection with FIGS. 1 to 4 and 7 and 8 above.Accordingly, the valves N-1 and N-2 are connected so that the passage offluid Vfrom the operating chamber 234 and the passage of uid to theoperating chamber 235 are restricted to the extent determined by thesetting of the needle valve portion 80. The details of construction ofthe ejector-strainer 36 and pilot valve P have been previouslydescribed. The system differs from that of FIGS. l and 2 primarily linthat two needle and check valves, N-l and N-2, are employed to controlthe opening and closing rates of the valve M41. The installation of thevalves N-1 and N-2, as shown in FIG. 5 is such that the valve M-1becomes a fast closing and a slow opening valve. VAccordingly, the inletchamber 204 of the valve M-l is connected by conduit 35,ejector-strainer 36, valve N-1, and conduit 37, to the upper pressurechamber 234 of the valve M-l. The flow of fluid to and from the charnber234 is controlled by the pilot valve P, the inlet of which is connectedby conduit 38 to the ejector-strainer 36, and the outlet of which isconnected to the downstream chamber 205 of the valve M-l. The lowerpressure chamber 235 of the valve M-1 is connected by a conduit 250 tothe fitting 50 of valve N-2. A conduit 251 connects the downstreamchamber 205 of the valve M41 to the fitting 67 of the valve N-2, so thatvalve N-2 controls the interllow of fluid between outlet chamber 205 anddiaphragm chamber 235.

The valve M41 is adapted to function as a pressure reducer under controlof the pilot valve P, as `described in connection with FIGS. l and 2.However, the controls shown in FIG. 5 will provide a -fast closingoperation upon development of excessive pressure on the downstream side,and will cause the valve to open more slowly after the pressure has beenreduced to eliminate difficulties usually caused by fluttering orpulsation of delivery pressure. Accordingly, in operation, should thepressure in the downstream chamber 205 become excessive or greater thanthe set pressure of the pilot valve P, the pilot valve will close, asbefore described, and cause operating fluid at full line pressure to beadmitted into the upper chamber 234 of the valve M1. This lluid pressureon top of the diaphragm 203 plus the action of the spring 225 will forcethe valve disk assembly to a closed position and in doing so will forcefluid out of the lower chamber 235 through the conduit 250 and the valveN-2. 'Ihe valve N-2 is preferably arranged to permit full flow of liquidto discharge from the chamber 235 through conduit 251 into the outletchamber '205. Upon resumption of normal pressure, that is, reduction ofpressure below the set operating pressure of the pilot valve P in thedownstream line, the pilot valve P will again open and by-pass operatingfluid around diaphragm chamber 234 in the same manner described inconnection with FIG. 1. At the same time, spent operating fluid iswithdrawn from the chamber 234 through conduit 37 and needle valve N41at a rate `determined by the setting of the valve stem 72 thereof. Fluidwill also ow into the lower chamber 235 through valve N-2 at a ratedetermined by the setting of its valve stem, which should be such thatoperating fluid can be supplied to the chamber 235 at a rate slightly inexcess of that at which spent operating uid can flow from chamber 235through theV valve N-1. Consequently, both chambers 234 and 235 arealways full of fluid. As a general rule, it is preferred to effect thedesired controlled rate of operation of the main valve M-2 by adjustmentof the stem of the needle valve N-1 or N-2 to restrict the dischargefrom that chamber of the main valve from which operating fluid is beingexhausted. In the instant arrangement, Vthe rate of opening of the mainvalve M-l is restricted, and

1 1 consequently the valve N-l is adjusted to control the rate at whichoperating iiuid can be forced from the chamber 234 by the combinedaction of the operating fluid admitted into chamber 235 and linepressure acting upon the valve disk 2.20 tending to open the main valve.

FIG. 6 illustrates a further embodiment of the invention wherein a poweroperated valve M-1 of the type described in detail in connection withFIG. is associated With a control system such as that shown in FIGS 3and 4, in lieu of the valve M shown therein. The valve M-l in thisinstance functions as a quick opening and slow closing pressure reliefvalve, and during normal operating conditions would be in a closedposition. The valve M-l is adapted to quickly open upon development ofexcessive pressure on the inlet side thereof and is shown in such openposition in FIG. 6. In order for the valve to assume this position,pressure at -the inlet chamber 204 would be transmitted through conduit35, T 121 and conduit 122 to the control chamber 122:1 of the pilotvalve P-l. When the pressure is in excess of the set operating pressureof the pilot valve P-1, it will open, as explained in connections withFIGS. 3 and 4 above, and permit operating uid to be exhausted rapidlyfrom the upper pressure chamber 234 of the valve M-l through valve N-l,by lifting the disk 78 thereof oi its seat, through conduit 126, T 125,conduit 123a, pilot valve P-1 and conduit 39 to the downstream chamber205 of the valve M-1.

It will be understood that operating uid may be exhausted through theopen pilot valve P-l at a much faster rate than fluid can be admittedfrom the conduit 35 through the needle valve strainer assembly 124, thesetting of the needle valve 16S being such as to regulate llow in thisdirection. Hence, when the pilot valve P-1 is fully open, operatingtluid cannot be supplied in suilicient volume to close the main valveM-l. The installation of the valve N-1 in this assembly is such as -topermit rapid ow of fluid from the chamber 234 without any substantialrestriction. Fast opening of the valve M-1 is further facilitated byrapidly admitting operating iluid into the lower pressure chamber 235through conduit 252, valve N-2, and conduit 253, after the valve M-1 hasstarted to open. In this connection, the installation of the valve N-2is such that the check valve disk therein is raised to permit rapid flowof uid through this valve and into the lower pressure chamber 235. Afterrestoration of normal pressures in the upstream valve chamber 204, thatis, pressure below the set operating pressure of the pilot valve P-1,the valve P-1 will close and uid will be admitted into the upper chamber234 of valve M-1 at a rate controlled by the setting of the needle stemportion 80 of the valve N-I. Accordingly, line pressure will build up inthe chamber 234 and this, in addition, to the preseure of the spring 225will urge the valve member 220 to a closed position. At the same time,iuid in the lower chamber 235 will be forced out through conduit 252,valve N-2 and conduit 253 to exhaust into the downstream chamber 265 ofthe main valve M-l. It will be noted that the installation of the valveN2 also affords adjustment to be made to restrict thc rate at whichoperating fluid is exhausted from the chamber 235. Accordingly, eitherthe valve N-1 or the valve N-2, or both, may be made to control the rateat which the valve closes. Preferably the closing speed is primarilycontrolled by adjusting the valve N-2 to restrict the rate of exhaust offluid from chamber 235 under the force of pressure uid admitted intochamber 234 at a rate controlled by valve N-l.

I-t will be understood that the arrangement of the combined needle andcheck valves N-1 and N-2 in the systems shown in both FIGS. 5 and 6 maybe reversed, whereupon the rates of opening and closing of the mainvalves are reversed.

It will be understood that various changes may be 12 made in the detailsof construction and in the arrangement of the parts of the main valves,control valves, combined needle and check valves, and auxiliaryapparatus disclosed herein, without departure from the principles of theinvention or from the scope of the annexed claims.

I claim:

1. In combination, a duid-pressure operable valve, including an inletchamber, an outlet chamber, a pressure chamber for operating fluid, andclosure means responsive to pressure in said pressure chamber forcontrolling the iiow of operating fluid between said inlet and outletchambers; by-pass conduit means interconnecting said inlet chamber andoutlet chamber whereby a flow of operating fluid by-passing said closuremeans may be established; control means in said by-pass conduit meansresponsive to the pressure in said outlet chamber to control the ow ofuid through said by-pass conduit means; an ejector in said by-passconduit means upstream of said control means and means including acombined needle and check valve connecting said pressure charnber withsaid ejector so that operating fluid is supplied to said pressurechamber from the inlet chamber of said valve and is exhausted from saidpressure chamber to the outlet chamber of said valve in response to saidcontrol means, said combined needle and check valve being arranged torestrict the rate of flow of operating Huid from said pressure chamberand to permit substantially greater rate of flow of operating uid tosaid pressure chamber, whereby said valve may be quickly closed andrelatively slowly opened.

2. Means for controlling fluid tlow through a pipe line, comprising: amain valve adapted to be connected in said pipe line and having a bodyprovided with inlet and outlet chambers, and means including a pressurechambe'r for controlling the ow of operating fluid through said body;and control means communicating with said pressure chamber andresponsive to the uid pressure in said pipeline for supplying andexhausting operating fluid, said last-mentioned means including acombined needle and check valve having a housing provided with an inletport and an outlet port, a valve seat located in one of said ports, acheck valve member adapted to seat on said valve seat, said check valvemember comprising a disk, having a centrally located bore therein, andan adjustable needle valve stem mounted in said housing having a conicaland cylindrical portion extending into and through the bore in saiddisk, whereby substantially full iiow of operating iluid is permitted bysaid needle and check valve in one direction and a more restricted flowis permitted in the reverse direction, whereby said main valve is causedto open and close at diierent rates.

3. The combination defined in claim l, in which the control meansincludes a pilot valve in said by-pass conduit means, and means,responsive to the pressure in the outlet chamber and connected to saidpilot valve, to regulate the position of the pilot valve as a functionof the pressure in the outlet chamber.

4. The combination defined in claim l, including another pressurechamber, a member disposed between said pressure chambers movable inresponse to the pressure diierence between said pressure chambers, anoperating connection between said movable member and said closure means,conduit means connected with said other pressure chamber for admittingand exhausting operating fluid, and another combined needle and checkvalve connected with said latter conduit means to permit substantiallyfull ow of operating fluid in one direction and a restricted flow in areverse direction.

5. The combination dened in claim l, including another pressure chamber,a member disposed between said pressure chambers movable in response tothe pressure diierence between said pressure chambers, an operatingconnection between said movable member and said closure means,conduit`means connected with said other pressure chamber for admittingand exhausting operating iluid, and another combined needle and checkValve connected with said latter conduit means to permit substantiallyfull ow of operating fluid from said other pressure chamber and arestricted liow thereto.

6. Means for controlling iiuid ilow through a pipe line as dened inclaim 1, in which said control means includes a pilot Valve controllingthe supply and exhaust of operating uid, and pressure responsive means,connected to said pilot valve, subject to the pressure in said pipeline.

7. Means for controlling lluid flow through a pipe line as defined inclaim 2, in which the check valve remains seated, in response to flow tosaid pressure chamber, to permit substantial restricted iiow ofoperating fluid to said pressure chamber, and unseats, i-n response toflow from the pressure chamber, to permit a substantially greater flowof operating uid from said pressure chamber.

8. Means for controlling liuid flow through a pipe line as deiined inclaim 2, in which said control means includes conduit means conveying anoperating fluid under pressure, a branch line connected between saidconduit means and said pressure chamber for supplying and exhaustingoperating fluid, means, in said conduit means downstream of theconnection with the branch line, responsive to the fluid pressure in thepipe line, for controlling the flow of operating fluid in said conduitmeans and thereby the supply and exhaust of operating iluid to saidpressure chamber, said combined needle and check valve being disposed insaid branch line for restricting the rate of flow of operating fluidfrom said chamber and permitting a substantially greater rate of flow ofoperating fluid thereto.

9. Means for controlling fluid flow through a pipe line as defined inclaim 2, in which said main valve relieves excess pressure in said pipeline, and in which the control means is responsive to the pressure onthe inlet side of said main valve, and in which the check valve remainsseated in response to iiow of operating fluid to said pressure chamberand is unseated in response to ow of operating fluid from said pressurechamber, whereby the main valve may be quickly opened 1n respense tosaid control means and closed at a relatively restricted rate.

v10. Means for controlling lluid flow through a pipe line as defined inclaim 2, in which said main valve 1s movable to reduce pressure in saidline by restrlctlng ow therethrough, and in which the control means1ncludes conduit means conveying an operating iluid under pressure, abranch line connected between said condult means and said pressurechamber for supplying and exhausting operating fluid, pressureresponsive meansm said conduit means, downstream from the connectionwith the branch line, responsive to pressure varlatlons at the outletside of said main valve, for controlling the ow of operating fluid insaid conduit means, said combined needle and check valve being disposedin said branch line and restricting the rate of flow of operating Huidfrom said chamber, and permitting a substantially greater rate of ow ofoperating lluid thereto.

11. Means for controlling iluid flow through a pipe line as dened inclaim 2, in which said control means includes a byapass conduit meansinterconnecting said inlet and outlet chambers whereby a ow of operatingfluid bypassing said main valve is established, a diverting conduitconnected between said b-y-pass conduit means and said pressure chamberfor diverting operating uid from said by-pass conduit means to saidpressure cham ber, means connected in said by-pass conduit means,downstream from the connection with the diverting conduit and responsiveto the pressure on the outlet of said main valve, to control the flow ofuid in said by-pass conduit means and thereby control the pressure ofoperating uid in said pressure chamber for effecting the opening andclosing of said main valve, said combined needle and check valve beingdisposed in said diverting conduit.

12. Means for controlling uid ow through a pipe line as delined in claim2, in which said control means includes an operating uid supply conduitconnected with the inlet side of the main valve and an operating fluidexhaust conduit connected with the outlet side of the main valve, meansconnecting said conduits including `a branch line to said pressurechamber, pressure responsive means, responsive to the pressure on theinlet side of said main valve, controlling the exhaust of operatingiluid from said pressure chamber, means in said operating uid supplyconduit restricting the supply of operating fluid to said pressurechamber at a rate below that permitted by the operating pressure fluidexhaust control means, said combined needle and check valve beingdisposed in said branch line and restricting the ow of operating lluidto said pressure chamber and permitting the flow of operating fluid fromsaid pressure chamber at a substantially greater rate.

13. Means for controlling low through a pipe line as del'lned in claim2, wherein `said means for controlling the ilow of operating fluidthrough said body includes another pressure chamber, a member dispo-sedbetween said pressure chambers movable in response to the pressuredifference between said pressure chambers, an operating connectionbetween said movable member and said main valve, conduit means connectedto said other pressure chamber for admitting and exhausting operatingfluid, and another combined needle and check valve connected with saidlatter conduit means to permit substantially full iiow of operatingfluid in one direction and a restricted iiow in a reverse direction.

14. Means for controlling flow through a pipe line as defined in claim13, in which one combined needle and check valve restricts the -low ofoperating uid to one pressure chamber and per-mits a substantiallygreater rate of flow therefrom, and in which the other combined needleand check valve restricts the rate of liow from the other pressurechamber and permits a substantially greater rate of flow thereto.

15. Means for controlling uid flow through a pipe line as dened in claim13, in which the combined needle and check valve connected with the rstmentioned pressure chamber permits substantially unrestricted tlow ofoperating fluid therefrom and restricts the ow thereto, and in which thecombined needle and check valve in the conduit means connected with saidother pressure chamber restricts the liow of operating uid from saidpressure chamber and permits substantially unrestricted flow ofoperating fluid thereto.

16. Means for controlling uid ow through a pipe line as dened in claim13, in which the combined needle and check valve connected with thefirst mentioned pressure chamber restricts the ow of operating Huid fromsaid chamber and permits substantially unrestricted ow of operating uidthereto, and in which the combined needle and check valve in the conduitmeans connected with said other pressure chamber restricts the ow ofoperating iluid to said other pressure chamber and permits substantiallyunrestricted flow of operating uid therefrom.

References Cited in the le of this patent UNITED STATES PATENTS1,311,536 Smoot July 29, 1919 1,504,620 Good Aug. 12, 1924 1,814,530Spence July 14, 1931 2,000,002 Stockmeyer Apr. 30, 1935 2,417,217Schreck Mar. 11, 1947 2,603,192 Kensok July 15, 1952

